Retired




Description

The NorCal Keyer is an unbelievable value for $16.50.  You get a memory keyer, with 3 programmable 40-character memories, iambic A & B mode, straight key and bug mode, 2 beacon modes, and variable speed control by either a 100K pot or the paddles themselves.  The kit comes with all board mounted parts and a high quality printed circuit board with plated through holes, silkscreened legends and solder mask.  You will need to add a stereo jack of your choice and a 9V battery connector, if desired.  The kit comes with a 5V regulator and will take an externally-applied 7-to-18 volt power source with the regulator wired in.  You may also use a 3V watch battery if you bypass the regulator.  

Supporting Files

 NorCal Keyer manual in PDF format
 Quick Reference Chart (Word)
 Quick reference Chart (PDF)
 Beginning Builder's Construction Guide, by K8IQY


Tips

Here are a few Operating and Construction Tips that you might find useful in your NorCal Keyer project ...

1)  Socket - I'd recommend the use of a socket for the keyer IC.

2) Battery power:  6 volts is beyond the keyer IC specifications - I'd use a 4.5 or 3 volt battery, 2 or 3 AA or AAA cells, OR one lithium cell.  Note that at lower power supply voltages, the minimum speed pot setting will increase, mine went from 13 wpm to 18 wpm from 5V to 3V.

3) Low Power regulator:  The LM2936 from National Semiconductor is a pin compatible part to the 78L05 supplied with the kit, but the LM2936 will only use 7 ua at a 9V input while the 78L05 will be much higher.  The LM2936 is available in both 3 and 5 volt outputs in the TO-92 package.  This regulator should have extra capacitance on the output, a 2.2 uf or higher tantalum capacitor will do.  there are lower cost alternatives to the LM2936, notably the Seiko regulators available from Mouser, but they are not pin compatible with the 78L05.  One bonus of the LM2936 since  it's designed for the automotive environment, it can withstand polarity reversals and relativelyhigh voltage inputs without being damaged.  The down side of this part is the price.

4) If you want to add word spaces to a message, send the character:  di-dah-dah-dah-dit  each time you want a word space inserted.  This can be done at the end of a message to effect a controllable delay between beacon message sends.  One warning, the recording routine will chop off a word space at the end of a message, so you have to send X + 1 word spaces to get the desired X spaces.

5) Multipress problems:  If you are having trouble with multipresses, one alternative is a hardware solution using diodes.  See the document, "Stalking the wild Multipress" on my website: <http://jacksonharbor.home.att.net/stalkin.pdf>

6) Single lever paddle users and the mem+both problem:  Since a single lever paddle can only press either the dit or dah but not both at the same time, sending or recording the mem+both memory is a problem.  One other problem is that the 5 ditdah tune mode won't work either.  One solution is to install a push button switch near the paddle which can be used to press either the dit or dah while the paddle is used to press the other input.  Another solution is to use the diode scheme in idea 5 above.

7) The NorCal keyer IC will function in Tick/PK-x keyer sockets, the pinout is the same, however an additional resistor must be added on pin 4 to "pullup" the pin - a 10k resistor connected from pin 4 to pin 1 (the power supply pin) will work fine.  Why would you want to do this ?  It might be nice for rigs such as the NorCal 38 special or Red-Hot Radio  series where there is a Tick socket built into the rig.  With the PK-x series, a high value resistor (1 meg ohm is fine) should be connected from the sidetone output to ground to prevent the pin from "floating" which will consume more power.

8)  For lower power usage and longest keyer IC life, replace the supplied sidetone speaker with a piezo - the keyer active current usage should drop dramatically.  I like the Murata piezos available from Mouser (81-PKM22EPP-4001).

9)  NO VELCRO !  -  please don't use velcro to mount the keyer circuit board, one of the few times I've ever seen a damaged keyer IC was when the builder used velcro to mount/insulate the circuit board - something about that tearing action really generates the static charge separation !

10)  Another item to save power:  Use a 2n7000 transistor in place of the pn2222a supplied with the kit - the 2n7000 is pin compatible with the NPN part but it is a MOSFET and requires virtually no "drive" current.  Another possibility is the BS-170 MOSFET, but the pinout is "backwards", you'll have to turn it 180 degrees before inserting it in the pn2222a position.

11)  Substitute pot values:  Dave Hinerman,WD8CIV, mentioned that he used a 20k pot in place of the 100k value specified for the speed pot.  He changed the value of C4, the timing capacitor to .047 uf from .01 uf supplied with the kit.  Dave reports that this combination works fine.  The timing capacitor supplied with the kit is a polyester cap from Panasonic with a .2 inch lead spacing.  Another RC combination which should work is a 50k pot with a .022 uf cap - I haven't tried that one yet but I did try a .1 uf cap with a 10k pot and that did NOT work, so it looks like the 20k plus .047 uf cap might be the limit of this mod.

Any comments?  Please email them to: 

Best Regards,

Chuck Olson, WB9KZY
Jackson Harbor Press - Ham Radio Kits and more!
Washington Island, WI
http://jacksonharbor.home.att.net/


Page last updated: 06/29/2012, 10:15:32
Page Maintained by:
Copyright © 1993-2008, NorCal QRP Club, Inc. All rights Reserved.